Two new diphenyl ethers, 4-(2-carboxy-3-heptyl-5-methoxyphenoxy)-2-heptyl-6-hydroxybenzoic acid (micareic acid) (13), 4-(2-carboxy-3-heptyl-5-methoxyphenoxy)-2-heptyl-6-hydroxy-3-methoxybenzoic acid (methoxymicareic acid) (27) and a new depside, 4-(2-heptyl-6-hydroxy-4-methoxybenzoyloxy)- 2-heptyl-6-hydroxybenzoic acid (prasinic acid) (34) have been detected in chemical races of the lichen Micarea prasina Fr. and isolated and characterized as the corresponding methyl esters. The structure of the latter compounds has been confirmed by total synthesis. The key steps in the synthesis of the diphenyl ethers (14), (26) involved Ullmann-like condensation between the 3-chloro 2-enone (17) and the phenols (11), (31), and subsequent aromatization of the enol ethers (23) and (32). A biomimetic-type synthesis of methyl micareate (48) has also been achieved by treatment of the depside (33) with sodium hydride in dimethylformamide.

The depsidones dechloropannarin (I), isovicanicin (11) and allorhizin (16) have been isolated from Psoroma lichens and the structures confirmed by synthesis.

By gas chromatography-mass spectrometry and comparison with authentic samples, 2-hydroxy-5-methyl-l,4benzoquinone was identified for the first time in the salivary gland secretion of the termite soldiers of Odontotermes magdatenae, in addition to previously reported benzoquinones.

ABSTRACTwere synthesized by reactions o? methyl 2-bromo-2-phmylethanorrte 1 with oFthosubstituted arylaminea 2a -2c. Subsequent reductive alkylationofthe lactams with aodium hydride and-iodobthane afforded only the N-alkylated quinoxalinone 4a and benzothiazinone 4b. Lithium aluminium hydride reduction of the lactams 3 8 -3~ gave the dihydro-aerivatives 5a, 5b and 5c while similar reduction of the A-aIkylated lactams 4a and 4b yieldzd tlie unsafurated quinoxaline 6a and benzothiazine 6b respectively. Lead tetraacetate oxidation of the quinsxalinone 3a furnished-the unsaturated quinoxalinone 9 which was N-alkylated using sodiumborohydride in formic acid to give 10. Treatment of the 1actm.w 3a, 3b and 3c with phosphorus pentasulphide produGd only the quinoxalinethiol f l aEd benzsthiazinethione 12. dium ethoxide t b g i v e the S-al&latedTroducta 2 urd 2 respectively. The lactam quinoxalinone 3a, benzothiazinone 3b and benzothiazinone 3cCompounds 11 and 12 were alkylated with iodomzhane and so-

Abstract. Attention is drawn to certain errors in our recently reported mass spectral study a of the salivary gland secretion from soldier termites of Odontotermes magdalenae.