1. A computer implemented method for prefetching data at discontiguous storage locations in a transactional execution (TX) environment, the method comprising: executing a transaction-begin (TB) instruction for beginning execution, by a processor, of transactional execution (TX) of a transaction in a transactional mode, the executing the TB instruction causing initiating prefetching of memory data based on a list having a location specified by the TB instruction, the list having one or more entries, each entry of the list specifying a storage address of the memory data, each storage address corresponding to an address in a hierarchical cache structure comprising a main memory at a highest level and a local cache at a lowest level relative to a central processing unit of the computer system, wherein the prefetching comprises: initiating fetching, to cache lines of a cache, of the memory data corresponding to the addresses specified by the entries of the specified list.