The verification of asynchronous fault-tolerant distributed systems is challenging due to unboundedly many interleavings and network failures (e.g., processes crash or message loss). We propose a method that reduces the verification of asynchronous fault-tolerant protocols to the verification of round-based synchronous ones. Synchronous protocols are easier to verify due to fewer interleavings, bounded message buffers etc. We implemented our reduction method and applied it to several state machine replication and consensus algorithms. The resulting synchronous protocols are verified using existing deductive verification methods.