J . Am. Chem. Soc. 1982, 104, 6879-6881 Scheme I1 KI3CN
a,b,c
2-Bromo-3-(trimethylsilyl)propene. An Annulating Agent for Five-Membered Carbo- and Heterocycles
-
(CH,’3C0,CH,CH3),
70% c t t 30% C C t h i
,
uu j,k,l,m,n*
6879
II II
CH3CCCH3-I3Co,
BrCH,CH,Br, K1, CH,CH,OH, A. H,SO,, A. C,H, (-H,O), CH,CH,OH, A (50% overall). LiAlH,, THF (8570). e 40% HBr, H,SO, (80%). f (C,H,),P (82%). gn-BuLi, THF, cis-oct-4-enedial (35%). Br,, CH,Cl,, CH,COOH (73%). NaOCH,CH,OH, HOCH,CH,OH, THF, A (15%). 500 “C, 45 Br,, CH,CI,. H,, Pd/C. O,, torr of N,, 10 mL/min flow. CH,COCH,. (CH,),S.
’
Table 1. Calculated and Experimentala Relative Peak Intensities (in %) for the M’ Peak of Butanedione according to Various Mechanisms observed for unlabeled predicted butane- [ 2 + for spiro- ranm/e dione 2 + 21 [3.3] [3.3] dom obsd 86 96 39 41.2 44 41.5 51.5 59 49 58.5 87 4.0 34 42.4 88 0.0 14.5 2 10.3 7
