Previously1 we described a reaction of 2-alkynyl ethers and alkali amides in liquid ammonia leading to 3-alken-1-ynes in high yields.Bis-2-alkynyl ethers (R1 = -CHzC=CCHzR, I) also undergo the 1 ,Celimination reaction but here the yields of the enynes are moderate because of a peculiar side-reaction leading to a furan. The isolated 3,4-disubstituted furans I11 (yields 20-30 %), which are isomeric with the starting materials, may be the result of a base-catalyzed cyclization of intermediary bis-1 ,2-alkadienyl ethers 11 (another possibility is cyclization of RCHz-CH=C=CH -0-CHz-C = C-CHzR and subsequent isomerization of the resulting 3-alkylidene-4-(l-alkenyI)-2,3-dihyd; -\furan).

Solutions of lithiated cumulenic ethers and bis-ethers R2CH=C=C=C(Li)OR3 and R10CH=C=C=C(Li)OR3 can be obtained by treatment of the compounds R10CH(R2)C=CCHz0R3 and R10CH2C=CCH(OR3)z respectively with 2 equivalents of butyllithium in ether. Reaction of these solutions with HzO, DzO, methyl iodide, a-chloroethers or ketones gives the cumulenic compounds or their derivatives in good yields.Solutions of lithiated cumulenic thioethers R2CH=C=C=C(Li)SR3 are obtained in an analogous way, but hydrolysis affords the isomeric enynic thioethers R2CH=CHC=CSR3 in addition to the expected curnulenic thioethers R2CH=C=C=CHSR3. Elimination of R'OH from R10C(R2)zC=CCH(SR3)2 with 1 equivalent of C4HgLi leads to the cumulenic dit hioacetals ( R Z ) K = C =C = C(SR3)2.

In dimethyl sulfoxide I ,2,3-trienyl ethers RRC=C=C=CHOCHs (with R and R = alkyl or RR'C = cyclohexyl) are isomerised by potassium rertbutoxide, first to 1,2,4-and then to 1,3,5-trienyl ethers. In the case of R R C = cyclohexyl, thus with / \=C=C=CHOCH3, elimination of methanol takes place and further isomerisation finally leads to aromatisation to 1-propenylbenzene. Acid hydrolysis of CHz=C(CHa)CH=C=CHOCHs in dimethyl sulfoxide affords the aldehyde CHz=C(W3)CH=CHCHO.The 1,2,3-and 1,2,4-trienyl ethers have been metallated in the 1-position by lithium amide and butyllithium, and subsequently alkylated or hydroxyalkylated.-

Disubstituted acetylenes C 4 H K = C R are produced in the reaction of I-ethoxy-1-hexyne C4H!,C-COCzHs with organolithium or Grignard compounds RLi or RMgBr. The yields are moderate to satisfactory. Ethoxyethyne HC-COCzHs and phenyllithium CsHsLi afford phenylacetylene HCE CC6H5 (after hydrolysis) in moderate yield.The formation of acetylenes probably proceeds by an addition-elimination mechanism.In a previous paper we presented a new and simple route to l-alkynylamines (ynamines), consisting of conversion of 1 -alkynyl ethers with lithium dialkylamides 1. The intermediary of an adduct was considered likely:This reaction, in which the acetylenic ether acts as a n electrophilir * cdkynylation agent, has been extended to some other organolithium compounds, wz, CH3Li, n-C4HgLi, t-CdH ,Lj, 1-cyclohexenyllithium, a-thienyllithium, and phenyllithium. The expected products were obtained in moderate to good yields (see Table I):Phenylmagnesium bromide, when employed instead of phenyllithium, gave a poor result. A partial isomerization of dibutylacetylene C4HgC= CCJHB into the allene C~H .~C H = C = C H C~H B was observed in the reaction of ethoxyhexyne with an excess of butyllithium.* The usual alkynylation reagents (metal alkynylides) are nucleophilic. P. P.Montijn, E. Harryvan and L. Brundsma, Rec. Trav. Chim. 83, 121 I (1964).

0 II I-Acylthio-1-alkynes RC-S-CaC-R (R and R are alkyl) have been prepared in satisfactory yields from ethereal suspensions or solutions of alkynyl-0 II lithium R C = CLi, sulfur powder, and acyl bromides RC-Br. 0 II Addition of water at 60-70" to CHsC-S-C=C-n-C4Hg proceeds smooth-0 0 II I 1 1y with formation of C H~C -S -C H Z -C -~-C~H~. This product is identical 0 0 II II with a sample prepared from CHK-SNa and C4HgC-CHzCI.The reaction of alkali alkynylides with elementary sulfur, selenium, or tellurium in liquid ammonia, followed by alkylation, has proved to be a very useful method for the preparation of 1-alkynyl thioethers and the selenium and tellurium analogues 11 21 3~4 .RC=Ce + X + RC=CXe =+ R C a C X R (R= H oralkyl, R = alkyl, X = S, Se or Te) RCH =CHC= Ce -+ RCH =CH-Ca C X R RC a C -C = Ce + RC a C -C = C X R 1 L. Brandsma, H . E. Wuers, and