Methods of synthesizing 14-b-aminomorphans and salts thereof

A method for preparing a compound of Formula (1):

• or a salt thereof, wherein
• comprising combining a compound of Formula (2):
• or a salt thereof, with a compound having the formula R*—N═O,
• to form a cycloadduct;
• combining the cycloadduct with a reduction system,
• wherein
• R1 is selected from H, OH, OC1-3alkyl, or OC(═O)C1-3alkyl;
• R2 is selected from H, (CH2)nR8, wherein n is 1-4 and R8 is selected from C3-8cycloalkyl, and CH═CH2;
• R3 is selected from H or C(═O)X—Y—R7, wherein X is null, 0, or NH;
• Y is null, C1-4alkyl, C1-4alkyenyl, or C1-4alkynyl, and R7 is H, C1-4alkyl, C1-4alkyenyl, aryl, or C1-8heterocyclyl;
• R4 and R5 together form an oxo, or one of R4 and R5 is OH and the other of R4 and R5 is H;
• R6 is selected from OC1-4alkyl, OC(═O)C1-4alkyl, OSi(C1-4alkyl)3;
• and
• R* is C(═O)X′—Y′—R7′, wherein X′ is null, 0, or NH;
• Y′ is null, C1-4alkyl, C1-4alkyenyl, or C1-4alkynyl, and R7 is H, C1-4alkyl, C1-4alkyenyl, aryl, or C1-8heterocyclyl.