The photocycloaddition of acetylacetone with naphthols and their methyl ethers

Abstract

Whereas irradiation of a mixture of a naphthol (or its methyl ether) and acetylacetone with excitation of the naphthol component leads to no reaction, irradiation of a similar mixture with excitation of the acetylacetone component leads to its cycloaddition to the naphthalene derivative to give a cyclobutane as the primary photoproduct.

Synthesis of 3‐Oxatricyclo[7.2.0.01,5]undeca‐7,10‐dienes through Intramolecular Photocycloaddition Reactions of Alkenes to 1,8 a‐Position of Naphthalene Ring

“…Photocycloaddition reactions between naphthalene rings and alkenes are known to have five modes as shown in Scheme 1. Reaction at the 1,2‐position that have high double bond character is the most common, and is described in many reports [13–70] . Reaction at the 1,3‐position via a biradical leads to compounds having a 3‐oxatricyclo[3.3.0.0 2,8 ]oct‐3‐ene skeleton, which was also shown in our earlier extensive studies [17,44,66,67,70–74] .…”

“…The methoxy-substituted product trans-7 ac was crystallized, and the X-ray crystal structure was analyzed, confirming that it is the trans isomer (Figure 1c). [88] In the photoreactions of (E)-6 ba-bf, which were introduced a methoxy group at the 6-position of the naphthalene ring, the overall yield decreased to 17-53 % (entries [30][31][32][33][34][35]. As for the trans/cis ratio, the ratio of cis isomer increased slightly compared to the reactions of substrates without the methoxy group, even though the trans isomer was preferentially obtained.…”

“…Photoreactions of (E)-6 ab-af, ba-bf were also performed in a similar manner. (7), 91 (24), 108 (5), 115 (24), 128 (13), 141 (12), 165 (33), 178 (39), 191 (60), 202 (27), 215 (32), 241 (22), 254 (41), 268 (64), 280 (10), 299 (100, M + ); HRMS (EI +) calcd for C 21 H 17 NO: 299.1310, found: 299.1308. (cis-7 aa): 0.009 g, 20 % yield.…”

[2 +2] Photocycloaddition of acetylacetone to naphthoates: a diverse addition pattern

“…It is well documented that the photocycloaddition of the enols of P-diketones, generally known as the de Mayo reaction,s occurs with simple alkenes but rarely with an aromatic nucleus . 6 We now report the successful photoadditions of acetylacetone (AA) to methyl 1and 2-naphthoates (1-and 2-NpC02Me) and their diverse reaction patterns.…”