References
- Contribution No. 651 from the Institute of Organic Chemistry
- Nicolaou , K. C. , Magolda , R. L. and Claremon , D. A. 1980 . J. Amer. Chem. Soc. , 102 : 1404
- Ohuchida , S. , Hamanaka , N. and Hayashi , M. 1979 . Tetrahedron Lett. , : 3661
- Ansell , M. F. , Caton , M. P. L. and Stuttle , K. A. J. 1982 . Tetrahedron Lett. , : 1955
- Our conclusion after several attempts
- The low yield is probably a reflection of the difficulty involved in the cyclization of (4) (see Ref. 2)
- Traas , P. C. , Boelens , H. and Takken , H. J. 1976 . Tetrahedron Lett. , : 2287
- Ether does not interfere with the subsequent reaction
- Box , P. O. Aldrich Chemical Co., 355, Milwaukee, WI 53201, USA