E. Brenna et al., AROMATIC ANNULATION OF ALICYCLIC ALPHA,BETA-UNSATURATED ALDEHYDES - SYNTHESIS OF CHIRALLY SUBSTITUTED TETRAHYDRONAPHTHALENES, Synlett, (4), 1998, pp. 365
Chiral 2-tetrahydronaphthalene-carboxylic acid derivatives 3, 6, and 9
were prepared by functionalization of enantiopure terpenic unsaturate
d aldehydes 1, 4, 7 with l-(alpha-carbethoxy-beta-carboxyethyl)-phosph
onium betaine, followed by a cyclization reaction promoted by ethyl ch
loroformate under basic conditions.