UNEXPECTED HYDROXYSPIROLACTONE FORMATION UPON BAEYER-VILLIGER OXIDATION OF A TRANS-ALPHA-DECALONE (TRANS-OCTAHYDRONAPHTHALEN-1(2H)-ONE) ANDX-RAY STRUCTURE OF THE PRODUCT

trans-4,4,10-Trimethyl-9-decalone ns-5,5,8a-trimethyl-octahydronaphtha len-1(2H)-one; 1), when treated with trifluoroperacetic acid, gave the unexpected hydroxyspirolactone oxy-7,11,11-trimethyl-1-oxaspiro[5.5]u ndecan-2-one (6), in which the two new O-atoms were introduced in a 1, 2-trans relationship. The structure of this compound was conclusively proven by X-ray crystallography. The process involves the intermediacy of 7-membered lactone 2, the expected Baeyer-Villiger product, which could also be succesfully prepared under controlled conditions at 0 de grees in a buffered medium containing Na2HPO4.