An asymmetric Diels-Alder reaction, involving the protected naphthopurpurin (4) and the D- glucose-derived diene (9a), is used to assemble compound (22), which is transformed by way of compounds (26),(27) and (28) into (+)-bostrycin (3). An X-ray analysis of compound (28) confirms that (+)-bostrycin possesses the stereostructure (3) and, therefore, that (-)- bostrycin is its antipode, ie (2). The use of naphthazarin (14a) and juglone (14c) as ...