The pmr spectra of a number of trimethylsilyl ethers of simple alcohols have been reported: H.A. Bruñe, Chem. Ber., 97, 2829(1964. Comparison of their chemical shifts to those of the corresponding alcohols indicate an upfield of shift of the signal for the protons on the oxygenated carbon upon silylation. (12) A.

Papuanic acid from the bark resin of Calophyllum papuanum Lauterb. is shown to have the structure and absolute stereochemistry 29a by a combination of degradative, synthetic, and X-ray crystallographic methods. Isopapuanic acid, also present in the resin, is the C-2 epimer 3Oa. The stereochemistry and conformations of these compounds and their epimerixation and bromination products are discussed. The synthesis of a derivative of papuanic acid is described.

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SynopsisWood pulps highly reactive in both high-and low-catalyst cellulose acetate processes can be prepared by mercerization and then treatment with alkylene oxides; only trace levels of substitution are required. The fiber inactivating effects of mercerization after drying are overcome, and several acetate properties are improved by this process. The reactivity characteristics cannot he duplicated by similar modifications of nonmercerized fibers; in low catalyst processes such pulps actually show reduced reactivity.