The previously undisclosed stereochemistry of bicyclo[2.2.l]hept-5-ene-jn-hexanoyl-2-carboxylic acid(l.2) and related derivatives was determined by nmr analysis(3) and application of Fraser's rule(4.5). It was concluded that the compound in question Is the 3-m-n-hexanoyl-2-&-carboxyllc acid(I). This conclusion was supported by chemical evidence. that Is, I gave rise to the lodolactone II(~): lr(CHCl3) 5.58(lactone), 5,8l(ketone). In good yleld using the standard iodolactonization procedure(T). I was converted into the chloroketone(II1) by successive treatment with oxalyl chloride, excess dlazomethane, and hydrogen chloride. The low melting III boiling at 146-T'(O.2 mm): Ir(CHC13) 5.76(CCCH2Cl), 5.83(ketone); nmr(CDC13) 2 5.84(s, 2, COCH2C1), 6.2g(t. 1. 51. = 4 Hz, C-2-z H). was further characterized as the pyridlnlum chloride(IV)(6), mp 186' and the nltrone(V). mp 125'(6). The condensation product(V1) of III and the sodium enolate of dlmethyl 3ketoundecanoate(8) was cycllzed with alkali. The subsequent decarboxvlation in qulnollne followed by esterification with dlazomethane afforded VI:, which underwent pyrolysis at 165-180' giving VIII(methy1 ester of 15-dehydl ?B1)(6): uv(MeOH) 296 mp(F. 22.800); nmr(CDC13) r 2.35(d. 1. J = 15.5 Hz, C-13 '.45( d. 1. J = 15.5 Hz, C-14 H). Assuming that the C-13 and C-14 substitus 1 * Part I : M. Miyano and C. R. Dorn, Tetrahedron Letters, in press.