Reaction of Pd(OzCMe)2 with PhCH2NHz leads to either Pd(NH2CH2Ph)2(02CMe)2 or [Pd(NH2CH2Ph)4] [02CMe],. The X-ray crystal structure of [Pd(NHZCH2Ph),] [Cl] [02CMe] shows pairs of [Pd (NH2CH2Ph),12 + ions held together by hydrogen bonds from the NH proton to chlorine and oxygen atoms of the anions, and the absence of interactions between phenyl ring ortho protons and the metal. PhCH2NHMe reacts with Pd(02CMe)2 giving Pd(NHMeCH2Ph)2(OZCMe) and PhCHzNMe2 gives the cyclometallate [Pd(NMe2CH2Ph-C,N)(p-OzCMe)]2. 'H n.m.r. spectra indicate that the complexes Pd(NMezCH2Ph)(L)(02CMe)z (L = PhNH2, o-MeC6H4NHz) prepared from [Pd(L)(02CMe)(p-02CMe)12, contain an interaction of the benzylamine ortho aromatic protons with the metal whereas Pd(NHMeCHzPh)(L)(02CMe)z (L = o-MeC,H4NH2) does not. 'H n.m.r. analysis of PdC142-and PhCH2NMe2 in (2Hl)methanol at 400 MHz indicates a 1 : 1 reaction stoichiometry and metal-proton interactions in intermediates containing above-plane and in-plane geometry of the aromatic ring, before metallation takes place. A 400-MHz spectral analysis of Pd(02CMe), and PhCH2NMe2 in CDC1, suggests similarly orientated species arise in the reaction giving [Pd(NMezCHzPh-C,N)(p-OzCMe)]2.See for example Thompson,

Treatment of the 7-oxopodocarpic acid derivatives (1) and (3) with 2,3-dichloro-5,6-dicyanobenzoquinone affords the conjugated dienones (5) and (6) directly. The latter compounds have potential as optically active relays for the synthesis of 3-oxygenated diterpenoids . The stereochemistry of an epoxide (7) formed from the dienone (5) has been confirmed by X-ray crystallography.