(2S,3R,4'R,4a'R,6a'S,6b'R,8a'S,12a'S,12b'S,14a'S)-3-(benzyloxy)-4',5,5,12a'-tetramethylhexadecahydro-1'H,3H,10'H-spiro[furan-2,3'-naphtho[2',1':4,5]indeno[7a,1-c]pyran]-10',14'(9'H)-dione 在
(+)-10-camphorsulfonic acid 作用下,
以
1,2-二氯乙烷 为溶剂,
反应 3.5h,
以99%的产率得到(2R,3R,4'R,4a'R,6a'S,6b'R,8a'S,12a'S,12b'S,14a'S)-3-(benzyloxy)-4',5,5,12a'-tetramethylhexadecahydro-1'H,3H,10'H-spiro[furan-2,3'-naphtho[2',1':4,5]indeno[7a,1-c]pyran]-10',14'(9'H)-dione