Table 2.

Synthesis of optically active bicyclic cycloheptenone derivatives via tandem 5-exocyclization/Claisen rearrangement.

entry	allyl alcohol (3)	bicyclic ketone (4)	yield (%)a	dr	ee (%)b
1	3a	4a	62		85
2	3b	4b	77		87
3	3c	4c	78	92:8	85
4	3d	4d	82	77:23	89
5	3e	4e	76	92:8	84
6	3f	4f	79	83:17(91:9)c	95

^aCombined yield of both diastereomers.

^bEnantiomeric excess of the major diastereomer was determined either by chiral GC or chiral HPLC.

^cAfter 24 h of stirring in MeONa/MeOH at 25 °C.