Acetic acid (R)-2-methyl-3-[(2S,3R)-3-((Z)-3-tributylstannanyl-propenyloxy)-tetrahydro-pyran-2-yl]-1-((2R,3S)-2-vinyl-tetrahydro-pyran-3-yloxy)-propyl ester 在
4 A molecular sieve 、 magnesium bromide 作用下,
以
二氯甲烷 为溶剂,
生成
(4aR,6S,7R,8R,9aS)-8-Methyl-6-vinyl-7-((2R,3S)-2-vinyl-tetrahydro-pyran-3-yloxy)-octahydro-1,5-dioxa-benzocycloheptene 、 (4aR,6S,7S,8R,9aS)-8-Methyl-6-vinyl-7-((2R,3S)-2-vinyl-tetrahydro-pyran-3-yloxy)-octahydro-1,5-dioxa-benzocycloheptene